1. Field of the Invention
The present invention relates generally to the fabrication of magnetic heads for hard disk drives, and more particularly to the fabrication and removal of seed layers utilized for electroplating magnetic head components such as induction coils and magnetic pole tips.
2. Description of the Prior Art
Several components of magnetic heads are typically fabricated utilizing electroplating processes, and a typical initial step in such electroplating processes is the deposition of an electrically conductive seed layer. A patterned photoresist is photolithographically fabricated upon the seed layer and the desired magnetic head component, such as an induction coil or a magnetic pole, is thereafter electroplated upon the seed layer within the patterned photoresist layer. Following the electroplating of the component, the photoresist layer is removed, and it is next necessary to remove the portions of the seed layer that are not covered by the electroplated component. The seed layer removal step is necessary to prevent electrical shorting of the components. In the prior art fabrication processes, an ion milling step or a sputter etching step is utilized to remove the seed layer.
The prior art seed layer removal step creates unwanted problems in magnetic heads. One problem is that portions of the removed seed layer become redeposited along the sides of the electroplated components. These redeposited seed layer portions can subsequently flake off and cause unwanted electrical shorting of the components. Additionally, the ion milling or sputter etching process also removes significant portions of the electroplated components that are exposed to it during the seed layer removal process. Thus, the electroplated components are plated up higher than would otherwise be necessary, such that after the seed layer removal process, the remaining thickness of the component is as desired. To fabricate the components with this additional thickness, the aspect ratio of the photoresist trenches must likewise be increased, and problems associated with the photolithographic fabrication of high aspect ratio trenches are encountered. Additionally, because it is necessary to ensure that the seed layer has been effectively removed from between the electroplated components, significant overetching is typically performed, which exacerbates the problems described hereabove. Additionally, the overetching can damage layers and structures beneath the seed layer.
As described below, the present invention solves these problems by utilizing a seed layer material that is susceptible to a reactive ion etch (RIE) removal process. Utilizing this RIE seed layer removal process, the seed layer redeposition problem is eliminated, the additional thicknesses of the components is not required, however the electroplated components are not substantially attacked by the RIE process, and seed layer overetching is not a problem because layers beneath the seed layer are not affected by the RIB process.